This request is for funds to purchase a microComputed Tomography (microCT) Skyscan 1272 (Bruker microCT, Contich, Belgium) ex vivo, high resolution system. The instrument will be housed at the Center for Craniofacial Regeneration of the University of Pittsburgh (UPitt) School of Dental Medicine and will function as a part of the Center's microCT core, which presently operates an in vivo microCT system housed at the UPitt BridgeSide Point 2 animal facility. The microCT systems that are currently available at UPitt and the other academic institutions in Pittsburgh are of the in vivo type and capable of intermediate resolutions (maximum resolution corresponding to 10.5?m voxel size). Although they provide an essential service to many investigators, these instruments cannot attain the image resolution (corresponding to a 1-8?m voxel size range) needed for the studies described in this application; they have been designed for longitudinal studies of relatively larger anatomical structures in animals. Five major users and three minor users based in several departments at UPitt and Carnegie Mellon University participate in the application with a combined need for 1500 hours of instrument use per year. To ensure an efficient operation of the system with minimal downtime, the system will be operated by a dedicated, full-time expert technical specialist. Half of the specialist's salary for four years will be covered by funds made available for this grant by the Dean of the School of Dental Medicine, while the remainder will be recovered from fees charged to the users. The funds necessary for ensuring the proper function of the instrument (service contract, a technician's effort for operation of the system) have been guaranteed for the life of the instrument from the School of Dental Medicine in the case of shortfalls in revenue. Based on the capabilities of the requested instrument, our expertise, facilities, computing/software infrastructure and the financial support commitment by the School of Dental Medicine, we anticipate being able to provide high quality data to the researchers participating in the application in a timely manner and at an affordable cost.